rangeRight

util

This method is like range except that it populates values in descending order.

Installation

Import

import { rangeRight } from '@tulx/utils';

Source Code

Implementation

/**
 * This method is like range except that it populates values in descending order.
 *
 * @param start - The start of the range.
 * @param end - The end of the range.
 * @param step - The value to increment or decrement by.
 * @returns Returns the range of numbers.
 *
 * @example
 * ```ts
 * rangeRight(4); // [3, 2, 1, 0]
 * rangeRight(-4); // [-3, -2, -1, 0]
 * rangeRight(1, 5); // [4, 3, 2, 1]
 * rangeRight(0, 20, 5); // [15, 10, 5, 0]
 * rangeRight(0, -4, -1); // [-3, -2, -1, 0]
 * rangeRight(1, 4, 0); // [1, 1, 1]
 * rangeRight(0); // []
 * ```
 */
export function rangeRight(
  start: number,
  end?: number,
  step?: number
): number[] {
  if (end === undefined) {
    end = start;
    start = 0;
  }

  if (step === undefined) {
    step = start < end ? 1 : -1;
  }

  if (step === 0) {
    return Array(Math.abs(end - start)).fill(start);
  }

  const result: number[] = [];
  let current = start;

  if (step > 0) {
    while (current < end) {
      result.push(current);
      current += step;
    }
  } else {
    while (current > end) {
      result.push(current);
      current += step;
    }
  }

  return result.reverse();
}

Example

import { rangeRight } from '@tulx/utils';

rangeRight(4); // [3, 2, 1, 0]
rangeRight(-4); // [-3, -2, -1, 0]
rangeRight(1, 5); // [4, 3, 2, 1]
rangeRight(0, 20, 5); // [15, 10, 5, 0]
rangeRight(0, -4, -1); // [-3, -2, -1, 0]
rangeRight(1, 4, 0); // [1, 1, 1]
rangeRight(0); // []

Related Functions

attempt

Attempts to invoke func, returning either the result or the caught error object.

bindAll

Binds methods of an object to the object itself, overwriting the existing method.

cond

Creates a function that iterates over pairs and invokes the corresponding function of the first predicate to return truthy.

conforms

Creates a function that invokes the predicate properties of source with the corresponding property values of a given object.

constant

Creates a function that returns value.

defaultTo

Checks value to determine whether a default value should be returned in its place.